How to programmatically create a client side file in Javascript that can be downloaded by the user? [duplicate]

Answer 1

One way to do this without having to use the filesystem is to create blobs. Let's say we have a bunch of data (in your case, from a form) and we wish to save it to a text "file". We could actually do something as follows:

var formBlob = new Blob([someStringVariable], { type: 'text/plain' });

From here, we could link a user to download this as an actual file like so:

someLink.href = window.URL.createObjectURL(formBlob);

If we wanted this data to persist, we could serialize our blob as a base64 string and save it to localStorage or any other persistent type of storage. Converting blobs to base64 is a bit beyond the scope of this answer but you can find a good reference/library here: http://blog.danguer.com/2011/10/24/base64-binary-decoding-in-javascript/